00000001 - Document - Cover link:presentationLink link:calculationLink link:definitionLink 00000002 - Statement - UNAUDITED CONSOLIDATED BALANCE SHEETS link:presentationLink link:calculationLink link:definitionLink 00000003 - Statement - UNAUDITED CONSOLIDATED BALANCE SHEETS (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 00000004 - Statement - UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME link:presentationLink link:calculationLink link:definitionLink 00000005 - Statement - UNAUDITED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDER'S DEFICIT link:presentationLink link:calculationLink link:definitionLink 00000006 - Statement - UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS link:presentationLink link:calculationLink link:definitionLink 999007 - Disclosure - Organizations and reorganizations link:presentationLink link:calculationLink link:definitionLink 999008 - Disclosure - Summary of principal accounting policies link:presentationLink link:calculationLink link:definitionLink 999009 - Disclosure - Concentration of risks link:presentationLink link:calculationLink link:definitionLink 999010 - Disclosure - Inventories link:presentationLink link:calculationLink link:definitionLink 999011 - Disclosure - Prepayments and other current assets link:presentationLink link:calculationLink link:definitionLink 999012 - Disclosure - Property and equipment, net link:presentationLink link:calculationLink link:definitionLink 999013 - Disclosure - Short-term borrowings link:presentationLink link:calculationLink link:definitionLink 999014 - Disclosure - Advances from customers link:presentationLink link:calculationLink link:definitionLink 999015 - Disclosure - Goodwill link:presentationLink link:calculationLink link:definitionLink 999016 - Disclosure - Operating leases link:presentationLink link:calculationLink link:definitionLink 999017 - Disclosure - Accrued expenses and other current liabilities link:presentationLink link:calculationLink link:definitionLink 999018 - Disclosure - Related party transactions link:presentationLink link:calculationLink link:definitionLink 999019 - Disclosure - Selling and marketing expenses link:presentationLink link:calculationLink link:definitionLink 999020 - Disclosure - General and administrative expenses link:presentationLink link:calculationLink link:definitionLink 999021 - Disclosure - Research and development expenses link:presentationLink link:calculationLink link:definitionLink 999022 - Disclosure - Income Taxes link:presentationLink link:calculationLink link:definitionLink 999023 - Disclosure - Shareholders’ Equity link:presentationLink link:calculationLink link:definitionLink 999024 - Disclosure - Commitments and Contingencies link:presentationLink link:calculationLink link:definitionLink 999025 - Disclosure - Subsequent events link:presentationLink link:calculationLink link:definitionLink 999026 - Disclosure - Other (loss)/income, net link:presentationLink link:calculationLink link:definitionLink 999027 - Disclosure - Other (loss) income, net link:presentationLink link:calculationLink link:definitionLink 999028 - Disclosure - Summary of principal accounting policies (Policies) link:presentationLink link:calculationLink link:definitionLink 999029 - Disclosure - Organizations and reorganizations (Tables) link:presentationLink link:calculationLink link:definitionLink 999030 - Disclosure - Summary of principal accounting policies (Tables) link:presentationLink link:calculationLink link:definitionLink 999031 - Disclosure - Inventories (Tables) link:presentationLink link:calculationLink link:definitionLink 999032 - Disclosure - Prepayments and other current assets (Tables) link:presentationLink link:calculationLink link:definitionLink 999033 - Disclosure - Property and equipment, net (Tables) link:presentationLink link:calculationLink link:definitionLink 999034 - Disclosure - Short-term borrowings (Tables) link:presentationLink link:calculationLink link:definitionLink 999035 - Disclosure - Advances from customers (Tables) link:presentationLink link:calculationLink link:definitionLink 999036 - Disclosure - Goodwill (Tables) link:presentationLink link:calculationLink link:definitionLink 999037 - Disclosure - Operating leases (Tables) link:presentationLink link:calculationLink link:definitionLink 999038 - Disclosure - Accrued expenses and other current liabilities (Tables) link:presentationLink link:calculationLink link:definitionLink 999039 - Disclosure - Related party transactions (Tables) link:presentationLink link:calculationLink link:definitionLink 999040 - Disclosure - Selling and marketing expenses (Tables) link:presentationLink link:calculationLink link:definitionLink 999041 - Disclosure - General and administrative expenses (Tables) link:presentationLink link:calculationLink link:definitionLink 999042 - Disclosure - Research and development expenses (Tables) link:presentationLink link:calculationLink link:definitionLink 999043 - Disclosure - Income Taxes (Tables) link:presentationLink link:calculationLink link:definitionLink 999044 - Disclosure - Other (loss)/income, net (Tables) link:presentationLink link:calculationLink link:definitionLink 999045 - Disclosure - Organizations and reorganizations (Details) link:presentationLink link:calculationLink link:definitionLink 999046 - Disclosure - Organizations and reorganizations (Details 1) link:presentationLink link:calculationLink link:definitionLink 999047 - Disclosure - Organizations and reorganizations (Details Narrative) link:presentationLink link:calculationLink link:definitionLink 999048 - Disclosure - Summary of principal accounting policies (Details) link:presentationLink link:calculationLink link:definitionLink 999049 - Disclosure - Summary of principal accounting policies (Details 1) link:presentationLink link:calculationLink link:definitionLink 999050 - Disclosure - Summary of principal accounting policies (Details 2) link:presentationLink link:calculationLink link:definitionLink 999051 - Disclosure - Summary of principal accounting policies (Details Narrative) link:presentationLink link:calculationLink link:definitionLink 999052 - Disclosure - Concentration of risks (Details Narrative) link:presentationLink link:calculationLink link:definitionLink 999053 - Disclosure - Inventories (Details) link:presentationLink link:calculationLink link:definitionLink 999054 - Disclosure - Inventories (Details Narrative) link:presentationLink link:calculationLink link:definitionLink 999055 - Disclosure - Prepayments and other current assets (Details) link:presentationLink link:calculationLink link:definitionLink 999056 - Disclosure - Property and equipment, net (Details) link:presentationLink link:calculationLink link:definitionLink 999057 - Disclosure - Property and equipment, net (Details Narrative) link:presentationLink link:calculationLink link:definitionLink 999058 - Disclosure - Short-term borrowings (Details) link:presentationLink link:calculationLink link:definitionLink 999059 - Disclosure - Advances from customers (Details) link:presentationLink link:calculationLink link:definitionLink 999060 - Disclosure - Advances from customers (Details 1) link:presentationLink link:calculationLink link:definitionLink 999061 - Disclosure - Goodwill (Details) link:presentationLink link:calculationLink link:definitionLink 999062 - Disclosure - Goodwill (Details Narrative) link:presentationLink link:calculationLink link:definitionLink 999063 - Disclosure - Operating leases (Details) link:presentationLink link:calculationLink link:definitionLink 999064 - Disclosure - Operating leases (Details 1) link:presentationLink link:calculationLink link:definitionLink 999065 - Disclosure - Operating leases (Details 2) link:presentationLink link:calculationLink link:definitionLink 999066 - Disclosure - Operating leases (Details Narrative) link:presentationLink link:calculationLink link:definitionLink 999067 - Disclosure - Accrued expenses and other current liabilities (Details) link:presentationLink link:calculationLink link:definitionLink 999068 - Disclosure - Related party transactions (Details) link:presentationLink link:calculationLink link:definitionLink 999069 - Disclosure - Related party transactions (Details 1) link:presentationLink link:calculationLink link:definitionLink 999070 - Disclosure - Selling and marketing expenses (Details) link:presentationLink link:calculationLink link:definitionLink 999071 - Disclosure - General and administrative expenses (Details) link:presentationLink link:calculationLink link:definitionLink 999072 - Disclosure - Research and development expenses (Details) link:presentationLink link:calculationLink link:definitionLink 999073 - Disclosure - Income Taxes (Details) link:presentationLink link:calculationLink link:definitionLink 999074 - Disclosure - Income Taxes (Details 1) link:presentationLink link:calculationLink link:definitionLink 999075 - Disclosure - Income Taxes (Details 2) link:presentationLink link:calculationLink link:definitionLink 999076 - Disclosure - Income Taxes (Details 3) link:presentationLink link:calculationLink link:definitionLink 999077 - Disclosure - Income Taxes (Details 4) link:presentationLink link:calculationLink link:definitionLink 999078 - Disclosure - Income Taxes (Details Narrative) link:presentationLink link:calculationLink link:definitionLink 999079 - Disclosure - Shareholders’ Equity (Details Narrative) link:presentationLink link:calculationLink link:definitionLink 999080 - Disclosure - Advances from customers (Details - Advances rollforward) link:presentationLink link:calculationLink link:definitionLink